1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
|
# This file is part of Config::AST -*- perl -*-
# Copyright (C) 2017-2019 Sergey Poznyakoff <gray@gnu.org>
#
# Config::AST is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 3, or (at your option)
# any later version.
#
# Config::AST is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with Config::AST. If not, see <http://www.gnu.org/licenses/>.
package Config::AST::Root;
use strict;
use warnings;
=head1 NAME
Config::AST::Root - root of the abstract syntax tree
=head1 DESCRIPTION
An auxiliary class representing the root of the abstract syntax tree.
It is necessary because the tree itself forms a circular structure
(due to the B<root> attribute of B<Config::AST::Node::Section>). Without
this intermediate class (if B<root> pointed to B<Config::AST> itself),
the structure would have never been destroyed, because each element
would remain referenced at least once.
=head1 CONSTRUCTOR
=head2 $obj = new($ci)
I<$ci> is one to enable case-insensitive keyword lookup, and 0 otherwise.
=cut
sub new {
my ($class, $ci) = @_;
bless { _ci => $ci }, $class;
}
=head1 METHODS
=head2 $s = $r->mangle_key($name)
Converts the string I<$name> to a form suitable for lookups, in accordance
with the _ci attribute.
=cut
sub mangle_key {
my ($self, $key) = @_;
$self->{_ci} ? lc($key) : $key;
}
=head2 $r->reset
Destroys the underlying syntax tree.
=cut
sub reset { delete shift->{_tree} }
=head2 $t = $r->tree
Returns the root node of the tree, initializing it if necessary.
=cut
sub tree {
my $self = shift;
return $self->{_tree} //=
new Config::AST::Node::Section($self,
locus => new Text::Locus);
}
=head2 $bool = $r->empty
Returns true if the tree is empty.
=cut
sub empty {
my $self = shift;
return !($self->{_tree} && $self->{_tree}->keys > 0);
}
=head1 SEE ALSO
L<Config::AST>.
=cut
1;
|
